You might not really give them a second thought, but batteries have become part of our lives. Without them, we’d have no mobile phones, remote controls or cars! However, since the 1800s, when the first battery was invented, there has been significant improvement and changes.
Now, there are many types of batteries available in the market and it’s essential to use the right one for each device. Among the most common types is the LR43 battery or button battery. Primarily used in small devices that don’t require a lot of power, you’ll typically find them in your wristwatch and in small clocks.
So, what exactly are button batteries? Are they safe to handle, and what amount of power do they produce?
Continue reading this article to learn more!
What is Button Batteries?
Button batteries are single-cell batteries that are squat cylindrically shaped. They are mainly between 5 – 25mm in diameter and 1 – 6mm thick. Additionally, they are among the smallest battery cells available and around the size of a button, hence its name.
The positive terminal of the cell is usually made from stainless steel, while the negative terminal is from a metal top cap. The devices that use these batteries usually serve continuously for a long period of time that can easily be as long as a year.
But, what makes the button batteries stay alive for such a long time? Well, it is because of their low discharge rates. While most batteries undergo a self-discharge process, button batteries have an insignificant amount.
A good example is a hearing-aid, which uses zinc-air batteries. They have a higher capacity for a specific size but dry within weeks of usage. This happens even if it’s not being used.
Button batteries are single cells and cannot be recharged, thus disposable. The anode is mainly made from zinc and lithium. The cathode often comes from manganese dioxide, cupric oxide, silver oxide, or carbon monoxide. Initially, mercuric oxide was used to make them but was dumped due to hazardous effects on the environment.
Types of Button Batteries and Their Chemical Properties
Like any other battery, button cells also have a lot of chemistry to their performance. Different sizes and shapes come with various parameters that react in different ways. They also come in different types, such as the LR43 battery that is very popular.
To know more about this, let look at some varieties of button batteries.
Alkaline batteries:
They are usually made of the same size as ordinary button batteries but have less capacity and voltage. This is because they are cheaper compared to silver dioxide and lithium cells. It has a capacity of 150mAh and a 3 – 9 ohms resistance.
Silver cells:
These button cells have a stable voltage but usually drop towards the end of life. Their capacities range from 250 – 200mAh while voltage may be relatively constant or gradually reduced.
Mercury batteries:
These types of button batteries come with stable voltage. But as said earlier, most counties have banned their use due to its toxicity. The average weight of the battery is 2.6g and offers a capacity of about 200mAh.
Zinc-Air Batteries:
You get a higher capacity for this type of battery. This is because it uses air as a depolarizer. They are air-tight, meaning they do not discharge more compared to other types of batteries. With this kind of battery, you should expect a capacity of 620 mAh, which is higher than all other button cells.
Rechargeable Variants
While there are many single-use button batteries in the market, some have a rechargeable feature. They also come in the exact sizes as the disposable batteries. However, they often have an improved capacity, thus having a lower energy retention time than single-use cells.
One of the main reasons for having a rechargeable button battery is backup. They are there to ensure that the system settings in a device are not altered in case of a power failure.
Some of the most commonly used rechargeable button batteries are the Nickel-Cadmium (NiCd). These are primarily used as backup batteries in computers.
It’s no doubt that rechargeable batteries are great because of the environmental benefits. However, most people don’t mind having disposable button batteries. This is because of their long life, and after all, they are only used on devices that require low power.
Health Issues
One of the biggest challenges the button battery industry faces is health issues. The main reason for this is because they are attractive to kids. This means the children are often tempted to put them in their mouth.
If ingested, the cell can cause severe damage to internal body organs. The cell reacts with different stomach chemicals such as mucus and saliva and creates a circuit. This ends up releasing a toxic alkali that can burn through body tissues.
The swallowed batteries can damage the esophagus and create holes within two hours. The batteries even cause a passage from the esophagus to the trachea in some cases. Sometimes they even burn through blood vessels around the chest.
Statistics show that over 3,000 cases of button battery ingestion are reported yearly in the United States alone. This is a significant concern since the health hazards are extreme and fatal. Some button battery manufacturing companies like Duracell have put measures to reduce these risks. They have started coating the cells with a bitter substance to discourage kids from swallowing them
Conclusion
So, overall, button batteries are handy sources of energy and are perfect for powering small devices. They can be used in wristwatches, pocket calculators, and toys, all with the advantage of very long life span.
There are many different button batteries, each with its own features. Although the mercury-based button battery is very good, it is hazardous and so is not as popular as it once was.
It is also important to note that button batteries are hazardous when swallowed. They can cause irreversible damage and can even lead to death. So, make sure that your store them well away from curious toddlers!
